Field
The present disclosure relates to systems and methods for improving efficiency, performance and durability of vehicles during gearshifts and, more particularly, for controlling a rotational speed of an engine by a motor prior to a shift occurring.
Description of the Related Art
Processors are being designed to be smaller, faster, more efficient and less expensive than ever. Due to the increased capabilities and reduced costs, vehicle manufacturers have been including more processors and processor-based functions in vehicles. For example, electronic control units (ECUs) now control many vehicle functions such as engine timing and transmission shifts. Use of ECUs frequently increases efficiency. For example, the efficiency of vehicles using processor-controlled engine timing is greater than the efficiency of vehicles using timing belt controlled engine timing.
ECUs have not solved all vehicle inefficiencies. For example, gear shifting in a standard transmission vehicle is still relatively inefficient. During a shift, the transmission disconnects the engine from the axle. After this disconnection, the engine throttle is controlled to cause the speed to increase or decrease to match a target engine speed. In particular, the throttle is closed during an upshift and opened during a downshift. This throttling causes efficiency loss and reduced performance of the vehicle.
Furthermore, the throttle control may not be sufficient to cause the engine speed to reach the target engine speed. When the gearshift is complete, the transmission forces the engine speed to further increase or decrease to match the rotational speed output by the transmission. This forced change of engine speed can shorten the life of the engine and transmission. Furthermore, the forced change of engine speed is unpleasant to some drivers.
Thus, there is a need for systems and methods for increasing efficiency, performance, and durability of vehicles during gearshifts.